Thin film solar cells composed of percolating networks of liquid electrolyte and dye-coated sintered titanium dioxide were developed by Dr. Michael Gratzel and coworkers at the Swiss Federal Institute of Technology. These photovoltaic devices fall within a general class of cells referred to as dye-sensitized solar cells (“DSSCs”). Conventionally, fabrication of DSSCs requires a high temperature sintering process (>about 400° C.) to achieve sufficient interconnectivity between the nanoparticles and enhanced adhesion between the nanoparticles and a transparent substrate.
To improve the performance of DSSCs, scientists have focused on enhancing molar extinction coefficients, spectral bandwidths, and charge transfer efficiencies of the sensitizing dyes. An effective method to improve the efficiency of charge transfer from the sensitizing dye to the nanoparticles and to reduce back electron transfer from the nanoparticles to the sensitizing dye has not, as of yet, been demonstrated.